Sous-chaîne la plus longue sans répéter les caractères
public class Solution
{
public int LengthOfLongestSubstring(string str)
{
var dict = new Dictionary<char, int>();
var max = 0;
int start = 0;
for (int i = 0; i < str.Length; i++)
{
var x = str[i];
if (!dict.ContainsKey(x))
{
dict.Add(x, 1);
}
else
{
dict[x] += 1;
while (start <= i && dict.ContainsKey(str[start]) && dict[x] > 1)
{
dict[str[start]]--;
if (dict[str[start]] == 0)
dict.Remove(str[start]);
start++;
}
}
max = Math.Max(max, i - start + 1);
}
return max;
}
}
PrashantUnity